The present invention relates to an openable guide for sewing machines for attaching circular elastic bands or rings to garments. The guide includes a folding means consisting of two opposed elements which are separatable from one another and which are operatively interconnected. One of these elements is connected to a control means which is biased toward a position in which the two elements are disposed in contiguous relation whereby their inner surfaces form a shaped channel within which an elastic ring forming the band is caused to slide. The control means is actuated in opposition to a biasing means and is effective in separating the two elements for the purpose of completing the sewing operation of one band and to facilitate the insertion of another elastic ring to be sewn onto the next workpiece.
In the manufacture of certain types of garments, more particularly, those having an elastic waist band, it is common knowledge to sew a closed elastic ring onto a garment which has been folded along its edges to form a belt with an internal cavity which, if necessary can be used to incorporate an additional piece of elastic. The operations of folding and attaching the belt to the garment are effected simultaneously be opposed folding guides that are selectively separable so as to permit insertion of elastic ring between the open elements of the guide and to complete the final portion of each sewing operation prior to removing the sewn garment from the machine.
It is necessary for the guides intended for this type of work to be separable because the elastic rings as such possess neither a beginning nor an end and it is therefore impossible to insert them in the guide in the conventional manner and the two edges of the elastic ring must be inserted within the two elements forming the shaped channel of the folding device along a section of corresponding length to the guide per se. As mentioned above, guides which are formed to define opposed channels that are located in an accessible position are known but they have certain limitations considered to be undesireable.
With certain types of conventional guides only one of the component elements is movable with respect to the other which remains fixed in the zone in which the elastic ring is slidable during the stitching operation. As a result, the available space between the two elements is limited making it difficult to insert a ring to be sewn which must be arranged therein in accordance with its width. The stationary element which is not movable from its fixed position obstructs the feed movement which the sewing machine operator performs with one hand during the final stages of the sewing operation. In other types of known guides the stationary element is formed by two members in such a way that the upper portion which forms a part of the channel in which the elastic ring slides, can be raised by tilting it outwardly. A counterbalanced handle is provided for tilting this upper portion of the stationary element.
The presence of a handle projecting from the upper part of the guide and the face that this portion of the guide is manually displaceable is considered to be a desireable feature. However, even with this feature it is not possible to overcome the limited space created by the size of the fixed portion which is fixed in the zone through which the elastic ring is caused to advance. With another conventional form of guide both of the opposed elements of the guide are horizontally movable with respect to one another, one part moving in one direction and the other in the opposite direction.
However, this form of guide also has its disadvantages due to the fact that the width of the passage cannot be increased so as to simplify the passage to feed the workpiece by the operator and at the same time minimize the height of the unit formed by the two elements of the guide.
There is no possibility of increasing the mutual displacement of these elements due to the fact that their movements are linear. If mechanisms were designed to provide additional displacement such mechanisms would require an excessively large lever system.
The object of the present invention is to obviate the above disadvantages by providing maximum freedom in the zone in which the guide according to the invention is operative and also to ensure that when the guide is open, the half channels provided in each of the elements forming the guide are located in the most advantageous position for receiving the edges of the elastic ring.
The technical problem to be solved in achieving this object is that of providing a guide of the aforementioned type in which the two opposed elements in addition to being movable with respect to one another for the purpose of inserting the elastic ring are also capable of reducing the height of the guide in the zone located forwardly of the sewing machine's presser foot.